Choose bit file name by serial number.
Choose bit file name by serial number.

Essentially copied from the Python driver. Now enumerates serial number lists on
open.

BBN-Q/libaps,BBN-Q/libaps2,BBN-Q/libaps2,BBN-Q/libaps2,BBN-Q/libaps,BBN-Q/libaps,BBN-Q/libaps2,BBN-Q/libaps2,BBN-Q/libaps,BBN-Q/libaps